1. Field of the Invention
The present invention is directed to apparatus for the placement of reinforcing steel in a variety of concrete structural members.
An essential aspect of reinforced concrete design involves the accurate placement and support of reinforcing steel bars in a concrete structural member. It is crucial that the reinforcing steel be precisely located and supported an adequate distance inside the face of the concrete. Failure to maintain the reinforcing steel a sufficient distance inward of the face of the concrete results in undesirable oxidation of the steel, necessitating very costly and extensive restoration of the structural member. The steel placement assembly of the present invention overcomes the problem of oxidation by accurately locating the steel reinforcement the optimum distance inside the concrete face.
The integrity of a concrete structural member is further determined by how effectively the reinforcing steel bars are locked into position within the concrete form to prevent unwanted shifting of the steel when the concrete is placed. The subject steel placement assembly prevents undesirable movement of the steel from design parameters and thereby enhances the ability of architects and engineers to design more efficiently. The attributes in design and placement of the reinforcing steel realized through utilization of the instant invention result in lower costs of construction and maintenance for reinforced structural members.
2. Prior Art
Several prior art patents are directed to supports or chairs for concrete reinforcing members. For example, U.S. Pat. No. 4,060,954 discloses a bar chair comprising a body member having tubular depending legs which snap onto the upwardly extending outer studs provided on the upper surface of an identical body member. Inside studs on the upper surface of each body member cooperate with the outer studs to retain various sizes of reinforcing bars.
U.S. Pat. No. 2,194,834 discloses a reinforced concrete stool comprising an upper section which fits over a lower section that has formed therein a notch for receiving a reinforcing rod. Similarly, U.S. Pat. No. 1,672,852 shows a support for a concrete reinforcing member consisting of a flat base and an upright body having a bifurcation in its upper end for supporting a reinforcing member in proper relation.
Components for the horizontal and vertical spacing of tubular members are also known in the prior art. U.S. Pat. No. 3,464,661 is directed to a conduit spacer apparatus comprising identical spacer members which mate to form a plurality of recesses for retaining tubular conduit. Each spacer is provided with upwardly projecting tongues and downwardly opening tongue receiving receptacles. The upwardly projecting tongues of one spacer member are inserted into the receptacles of the spacer member to which it mates.
None of the prior art patents discloses an apparatus which is capable of positively locating and supporting reinforcing steel a desired distance within the face of the concrete. Furthermore, the prior art fails to provide a device which accurately locates the reinforcing steel to prevent undesired movement while the concrete is being placed. The present invention accomplishes the foregoing objectives while being adaptable to produce structural members of diverse sizes which require various reinforcement positions.